WWordGenerator.org GeneratorsWord ListsBlogAboutGenerate a word Home / I / index of refraction index of refraction noun 4 syllables 19 letters Scrabble 33 WWF 36 Definitions noun the ratio of the velocity of light in a vacuum to that in a medium refractive index Look “index of refraction” up elsewhere Wiktionary ↗ Merriam-Webster ↗ Etymonline ↗ Dictionary.com ↗ Want another word?Spin the dictionary for a fresh one. Generate a word →